Operativni sistem: Windows 7 Professional 64 (available through downgrade rights from Windows 8 Pro)
(This system is preinstalled with Windows 7 Professional software and also comes with a license and media for Windows 8.1 Pro software. You may only use one version of the Windows software at a time. Switching between versions will require you to uninstall one version and install the other version. You must back up all data (files, photos, etc. ) before uninstalling and installing operating systems to avoid loss of your data. )